Technical Fixture for narrowing Ford 8.8?

I ran across a picture of a plate that is bolted to the rearend cover opening and has slots in it for a measuring tape so you can locate your shortening cut correctly. Anyone know who is selling these?

 

Dutchman axles sells one for $25. It's called a measuring dogbone.

 

Mittler Brothers
https://www.mittlerbros.com/

 

egay 20 dollars. itc brand

 

Thanks!

 

No tubes on my 8.8.... It's got half shafts...

 

Ddi you use the whole "cradle" or make your own suspension mounts. I've looked at using the irs version - not in depth yet.
If you have a build link, send it my way.

 

Ummm..... it came in an o/t car....